Associations between body mass index, weight control concerns and behaviors, and eating disorder symptoms among non-clinical Chinese adolescents

BACKGROUND Previous research with adolescents has shown associations of body weight, weight control concerns and behaviors with eating disorder symptoms, but it is unclear whether these associations are direct or whether a mediating effect exists. This study was conducted to investigate the prevalence of overweight and obesity, weight control concerns and behaviors, and eating disorder symptoms and to examine the mediating function of weight control concerns and behaviors on the relationship between body mass index (BMI) and eating disorder symptoms among non-clinical adolescents in China. METHODS A cross-sectional survey among 2019 adolescent girls and 1525 adolescent boys in the 7th, 8th, 10th and 11th grades from seven cities in China was conducted. Information on weight control concerns and behaviors, and eating disorder symptoms (Eating Disorder Inventory-3) were collected from the adolescents using a self-administrated questionnaire. RESULTS Weight control concerns and behaviors, and eating disorder symptoms were prevalent among the study population. A high proportion of adolescents scored at or above the threshold on the eating disorder inventory (EDI) subscale such as bulimia, interoceptive deficits, perfectionism, and maturity fears, which indicated eating disorder symptoms. High BMI was significantly associated with high score of drive for thinness, body dissatisfaction, bulimia, low self-esteem, interceptive deficits and maturity fears, so do perceived body weight status. Almost all weight control concerns and behaviors we investigated were significantly associated with high EDI subscale scores. When weight control concerns were added to the model, as shown in the model, the association between BMI and tendency of drive to thinness and bulimia was attenuated but still kept significant. The association between BMI and body dissatisfaction were no further significant. The association of BMI and drive for thinness, body dissatisfaction and bulimia was considerably weaker than when weight control behaviors were not included. CONCLUSIONS Weight control concerns and behaviors may be mediators of the association between BMI and eating disorder symptoms. Interpretation of these weight control problems is crucial to develop culturally appropriate educational and intervention programs for adolescents.